Novel reactor for ionic liquid catalyzed alkylation based on motionless mixer

ABSTRACT

Systems and apparatus for ionic liquid catalyzed hydrocarbon conversion may comprise a modular reactor comprising a plurality of mixer modules. The mixer modules may be arranged in series. One or more feed modules may be disposed between the mixer modules. Such systems may be used for ionic liquid catalyzed alkylation reactions. Processes for ionic liquid catalyzed hydrocarbon conversion are also disclosed.

TECHNICAL FIELD

This disclosure relates to reactors, systems, and processes for ionicliquid catalyzed alkylation.

BACKGROUND

There is a need for apparatus, reactors, and systems for the efficientmixing of two or more immiscible liquids, such as ionic liquid catalystsand hydrocarbon feeds for ionic liquid catalyzed hydrocarbon conversionprocesses including ionic liquid catalyzed alkylation.

SUMMARY

In an embodiment there is provided a system for ionic liquid catalyzedhydrocarbon conversion, the system comprising a modular reactorcomprising a plurality of mixer modules and one or more feed modules.The mixer modules are arranged in series, each mixer module and eachfeed module is vertically aligned, and each mixer module is arrangedcoaxially with each feed module.

In another embodiment, there is provided a system for ionic liquidcatalyzed hydrocarbon conversion, the system comprising a modularreactor comprising a plurality of mixer modules and one or more feedmodules, and a feed supply line in fluid communication with each feedmodule. The mixer modules are arranged in series, each feed module isdisposed between two of the mixer modules, each mixer module and eachfeed module is vertically aligned, and each mixer module is coaxial witheach feed module.

In yet another embodiment there is provided a system for ionic liquidcatalyzed hydrocarbon conversion, the system comprising a modularreactor having a base and a top; and a circulation loop in fluidcommunication with the modular reactor. The circulation loop has a firstloop end coupled to the base of the modular reactor. The system isconfigured for withdrawing reactor effluent from the base of the modularreactor into the circulation loop. The circulation loop further has asecond loop end coupled to the top of the modular reactor. The system isfurther configured for delivering a recirculation stream to the top ofthe modular reactor. The modular reactor comprises a first static mixer;a first feed module disposed downstream from, and in fluid communicationwith, the first static mixer; and a second static mixer disposeddownstream from, and in fluid communication with, the first feed module.The first static mixer is coaxial with the first feed module and thesecond static mixer.

In still a further embodiment there is provided a process for ionicliquid catalyzed hydrocarbon conversion, the process comprisingwithdrawing reactor effluent from a modular reactor, the reactoreffluent comprising unreacted hydrocarbons from a hydrocarbon feed;adding ionic liquid catalyst to the reactor effluent to provide arecirculation stream; introducing the recirculation stream into a firstmixer module of the modular reactor; via the first mixer module, mixingthe recirculation stream to provide an ionic liquid/hydrocarbon emulsioncomprising the ionic liquid catalyst and the unreacted hydrocarbons; viaa first feed module, distributing the hydrocarbon feed at an elevationbetween the first mixer module and at least a second mixer moduledisposed downstream from the first mixer module; and via at least thesecond mixer module, mixing the hydrocarbon feed with the ionicliquid/hydrocarbon emulsion.

Further embodiments of systems and processes for ionic liquid catalyzedhydrocarbon conversion are described hereinbelow and shown in theDrawings. As used herein, the terms “comprising” and “comprises” meanthe inclusion of named elements or steps that are identified followingthose terms, but not necessarily excluding other unnamed elements orsteps.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B each schematically represent a system for ionic liquidcatalyzed hydrocarbon conversion processes, according to embodiments ofthe present invention;

FIG. 2 schematically represents a system for ionic liquid catalyzedhydrocarbon conversion processes, according to an embodiment of thepresent invention;

FIG. 3 schematically represents a modular reactor as seen from the side,according to an embodiment of the present invention;

FIG. 4A schematically represents components of a modular reactor inexploded view as seen from the side, according to an embodiment of thepresent invention;

FIG. 4B schematically represents a modular reactor as seen from theside, according to an embodiment of the present invention;

FIG. 4C schematically represents a modular reactor as seen along theline 4C-4C of FIG. 4B, according to an embodiment of the presentinvention;

FIG. 4D schematically represents a modular reactor as seen along theline 4D-4D of FIG. 4B, according to an embodiment of the presentinvention;

FIG. 5 schematically represents a modular reactor, as seen from theside, in combination with a circulation loop, according to an embodimentof the present invention;

FIGS. 6A and 6B each schematically represents a sparger for distributinghydrocarbon feed to a modular reactor, as seen in reverse plan view,according to embodiments of the present invention; and

FIG. 7 schematically represents a system and process for ionic liquidcatalyzed hydrocarbon conversion, according to another embodiment of thepresent invention.

DETAILED DESCRIPTION

Ionic liquid catalysts may be useful for a range of hydrocarbonconversion reactions, including alkylation reactions for the productionof alkylate, e.g., comprising gasoline blending components, and thelike. Systems for ionic liquid catalyzed hydrocarbon conversionaccording to this disclosure may comprise a modular reactor and at leastone circulation loop in fluid communication with the modular reactor,wherein each modular reactor may comprise a plurality of mixer modulesarranged in series.

Modular reactors as disclosed herein provide for the rapid and thoroughmixing of ionic liquid catalyst and hydrocarbon reactants so as togenerate a large surface area of ionic liquid catalyst phase in an ionicliquid/hydrocarbon mixture, thereby enabling highly efficient ionicliquid catalyzed hydrocarbon conversion processes on a commercial scale.

Systems for Ionic Liquid Catalyzed Alkylation

Although systems may be described herein primarily with reference toionic liquid catalyzed alkylation reactions, such systems may also beapplicable to other ionic liquid catalyzed hydrocarbon conversionreactions as well as to other processes more generally.

In an embodiment, a system for ionic liquid catalyzed hydrocarbonconversion processes may comprise a modular reactor comprising aplurality of mixer modules and one or more feed modules. Each of theplurality of mixer modules may be arranged in series. In an embodiment,each of the mixer modules and each of the feed modules may be arrangedvertically or upright. In an embodiment, each of the mixer modules andeach of the feed modules may be vertically aligned, and each of themixer modules may be arranged coaxially with each of the feed modules.

In an embodiment, the mixer modules may be arranged alternately with thefeed modules such that each feed module is disposed between two adjacentmixer modules. The mixer modules on top of the feed modules willtherefore produce highly turbulent flow field to allow rapid mixing inthe feed modules. The mixer modules and the feed modules may be stackedon top of each other such that each mixer module may be in contact withat least one of the feed modules, and each feed module may be in contactwith two adjacent mixer modules.

In an embodiment, the modular reactor may have one more mixer modulethan feed module. That is to say, for a modular reactor wherein thenumber of mixer modules is n, the number of feed modules may be (n−1).In an embodiment, the number of mixer modules per modular reactor may bein the range from two (2) to 10, or from two (2) to six (6), or from two(2) to four (4).

In an embodiment, each mixer module and each feed module may have acircular cross-section. In a sub-embodiment, the internal diameter ofeach mixer module may be the same or essentially the same as theinternal diameter of each feed module. In an embodiment, each mixermodule may occupy essentially the entire cross-sectional area of themodular reactor. In an embodiment, the modular reactor may be at leastsubstantially cylindrical.

In an embodiment, each mixer module may comprise a static mixer. In anembodiment, each mixer module may comprise at least one mixer element.In a sub-embodiment, the mixer element(s) may be disposed within acylindrical housing. In an embodiment, a surface of the mixer elementmay comprise a hydrophobic material. In an embodiment, each mixer modulemay comprise a material selected from a ceramic, an engineering plastic,and a metal alloy. In a sub-embodiment, the mixer module may compriseone or more metal alloys, e.g., selected from Monel®, Hastelloy®,stainless steel, and tantalum-coated stainless steel. In an embodiment,the mixer module may comprise one or more engineering plastics, e.g.,selected from polypropylene, Teflon®, polyvinylidene difluoride (PVDF),polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), andpolyoxymethylene (POM). In a sub-embodiment, a mixer module of themodular reactor may comprise a housing comprising a metal alloy and oneor more mixer elements comprising an engineering plastic.

A system for ionic liquid catalyzed hydrocarbon conversion processes mayfurther comprise a feed supply line. In an embodiment, each feed modulemay include a feed conduit. Each feed conduit may be in fluidcommunication with the feed supply line, and the system may beconfigured for delivering hydrocarbon feed to the modular reactor viaeach of the feed modules. Each feed module may be configured so as touniformly distribute the hydrocarbon feed over the entire cross-sectionof the modular reactor. In an embodiment, the hydrocarbon feed may beintroduced into the modular reactor at high speed sufficient to allowrapid mixing of the hydrocarbon feed stream with the liquid stream fromthe upper mixer module. In an embodiment, each feed module may comprisea sparger, such as a tree sparger or a ring sparger. In asub-embodiment, such a sparger may have a diameter in the range from 40to 100% of the internal diameter of each mixer module and of each feedmodule, or from 60 to 100% of the internal diameter of each mixer moduleand of each feed module, or from 90 to 99% of the internal diameter ofeach mixer module and of each feed module.

In an embodiment, the modular reactor may be configured for facileassembly and disassembly of the mixer modules to and from the feedmodules. In a sub-embodiment, each mixer module may be configured forfacile assembly to, and disassembly from, at least one of the feedmodules; and each feed module may be configured for facile assembly to,and disassembly from, two of the mixer modules. In an embodiment, eachmixer module may comprise a mixer module proximal flange at the mixermodule proximal end and a mixer module distal flange at the mixer moduledistal end.

In an embodiment, each feed module may comprise a feed module proximalflange at the feed module proximal end and a feed module distal flangeat the feed module distal end. The mixer module distal flange may beconfigured for coupling to a feed module proximal flange, such that themixer module distal end may be affixed to the proximal end of anadjacent, downstream feed module. In an embodiment, such affixation ofthe mixer module distal end to the feed module proximal end may bereversible. The feed module distal flange may be configured for couplingto the mixer module proximal flange of an adjacent, downstream mixermodule, such that the feed module distal flange may be affixed, e.g.,reversibly, to the mixer module proximal flange.

A system for ionic liquid catalyzed hydrocarbon conversion may furthercomprise a circulation loop in fluid communication with the modularreactor. The modular reactor may have a base and a top. The circulationloop may have a first loop end coupled to the base of the modularreactor, and the circulation loop may further have a second loop endcoupled to the top of the modular reactor. The system may be configuredfor withdrawing reactor effluent from the modular reactor via the firstloop end into the circulation loop. The system may be further configuredfor delivering a recirculation stream to the top of the modular reactorvia the second loop end. The circulation loop may comprise an ionicliquid catalyst inlet configured for adding fresh ionic liquid catalystto withdrawn reactor effluent to provide the recirculation stream; forexample, the recirculation stream may comprise withdrawn reactoreffluent in combination with freshly added ionic liquid catalyst. Thecirculation loop may further comprise a heat exchanger configured forcooling the recirculation stream.

According to another embodiment of a system for ionic liquid catalyzedhydrocarbon conversion, the system may comprise a modular reactorcomprising a plurality of mixer modules and one or more feed modules,and a feed supply line in fluid communication with each feed module. Themixer modules may be arranged in series. In an embodiment, each feedmodule may be disposed between two mixer modules. Each mixer module andeach feed module may be vertically aligned, and each mixer module may becoaxial with each feed module. In an embodiment, each mixer module mayoccupy a volume in the range from 10 to 50% of the total volume of themodular reactor.

In an embodiment, each feed module may include a feed conduit. Each feedconduit may be in fluid communication with the feed supply line, and thesystem may be configured for delivering hydrocarbon feed to the modularreactor via each feed module. In an embodiment, each mixer module may bein fluid communication with, and in contact with, at least one feedmodule. In an embodiment, each feed module may be in fluid communicationwith, and reversibly affixed to, two mixer modules.

In an embodiment, the system may further comprise a circulation loop influid communication with the modular reactor. The circulation loop mayhave a first loop end coupled to the base of the modular reactor and asecond loop end coupled to the top of the modular reactor. The systemmay be configured for withdrawing reactor effluent from the modularreactor via the first loop end into the circulation loop. Thecirculation loop may comprise an ionic liquid catalyst inlet configuredfor adding fresh ionic liquid catalyst to withdrawn reactor effluent toprovide a recirculation stream. The circulation loop may furthercomprise a heat exchanger configured for cooling the recirculationstream.

In an embodiment, the plurality of mixer modules may comprise a firstmixer module and at least a second mixer module disposed downstream fromthe first mixer module. The first mixer module may be in fluidcommunication with the second loop end for receiving the recirculationstream from the circulation loop. In an embodiment, the first mixermodule may be configured for mixing the recirculation stream such thatthe ionic liquid catalyst component of the recirculation stream isdispersed into an ionic liquid/hydrocarbon emulsion, wherein theemulsion may comprise small to microscopic droplets of the ionic liquidcatalyst, e.g., having a droplet diameter in the range from 1 to 1000microns, or from 5 to 500 microns, or from 10 to 250 microns. The systemmay be configured for distributing the hydrocarbon feed to the modularreactor, e.g., via each feed module, between each adjacent pair of mixermodules. Each subsequent (downstream) mixer module may be configured forthoroughly and rapidly mixing the distributed hydrocarbon feed with themixed recirculation stream emanating from the first mixer module.

According to a further embodiment of a system for ionic liquid catalyzedhydrocarbon conversion processes, the system may comprise a modularreactor and a circulation loop in fluid communication with the modularreactor. The circulation loop may have a first loop end coupled to thebase of the modular reactor and a second loop end coupled to the top ofthe modular reactor. The system may be configured for withdrawingreactor effluent from the base of the modular reactor into thecirculation loop, and the system may be further configured fordelivering a recirculation stream to the top of the modular reactor.

The modular reactor may comprise a first static mixer, a second staticmixer, and a first feed module disposed downstream from, and in fluidcommunication with, the first static mixer. The second static mixer maybe disposed downstream from, and in fluid communication with, the firstfeed module. The first static mixer may be coaxial with the first feedmodule and the second static mixer.

In an embodiment, the first feed module may be reversibly affixed to,and in contact with, each of the first static mixer and the secondstatic mixer. The modular reactor may further comprise a second feedmodule disposed downstream from, and in fluid communication with, thesecond static mixer. The modular reactor may further comprise a thirdstatic mixer disposed downstream from, and in fluid communication with,the second feed module. The first static mixer may be coaxial with thesecond feed module and the third static mixer. In an embodiment, eachstatic mixer may comprise a cylindrical housing and at least one mixerelement disposed within the cylindrical housing.

The second feed module may be reversibly affixed to, and in contactwith, each of the second static mixer and the third static mixer. In anembodiment, the first feed module may be configured for uniformlydistributing hydrocarbon feed at an elevation between the first staticmixer and the second static mixer. The second feed module may beconfigured for distributing hydrocarbon feed at an elevation between thesecond static mixer and the third static mixer. The use of multiple feedmodules for introducing hydrocarbon feed at different elevations of themodular reactor may serve to minimize the local olefin concentrationwithin the modular reactor so as to provide better reactor performanceand superior product(s), e.g., alkylate.

According to yet another embodiment, a process for ionic liquidcatalyzed hydrocarbon conversion, e.g., isoparaffin/olefin alkylation,may be practiced using systems as disclosed herein. Such systems maycomprise a modular reactor having a top and a base, and at least onecirculation loop in fluid communication with the top and the base of themodular reactor. The modular reactor may comprise a plurality of mixermodules. The modular reactor may further comprise at least one feedmodule. Hydrocarbon feed may be delivered to the modular reactor, e.g.,between adjacent mixer modules, via the at least one feed module. In anembodiment, each mixer module may be disposed vertically in series. Suchsystems for ionic liquid catalyzed hydrocarbon conversion may furthercomprise additional elements, features, and characteristics as describedherein and as shown in the drawings.

In an embodiment, such a process for ionic liquid catalyzed hydrocarbonconversion may include: withdrawing reactor effluent from the modularreactor, the reactor effluent comprising unreacted hydrocarbons from ahydrocarbon feed to the modular reactor; adding ionic liquid catalyst tothe reactor effluent to provide a recirculation stream; introducing therecirculation stream into a first (e.g., uppermost) mixer module of themodular reactor; via the first mixer module, mixing the recirculationstream to provide an ionic liquid/hydrocarbon emulsion comprising theionic liquid catalyst and the unreacted hydrocarbons; via a first feedmodule, distributing the hydrocarbon feed at an elevation between thefirst mixer module and at least a second mixer module disposeddownstream from the first mixer module; and via at least the secondmixer module, mixing the hydrocarbon feed with the ionicliquid/hydrocarbon emulsion. In an embodiment, the ionic liquid catalystmay be added to the reactor effluent at a rate sufficient to maintainthe overall ionic liquid catalyst volume in the modular reactor in therange from 0.5 to 50 vol %, or from 1 to 10 vol %, or from 2 to 6 vol %.

In an embodiment, such a process for ionic liquid catalyzed hydrocarbonconversion may further include adding a co-catalyst, or a catalystpromoter, or both a catalyst promoter and a co-catalyst, to the modularreactor. In an embodiment, such a co-catalyst may comprise an alkylchloride. A catalyst promoter for addition to the modular reactor maycomprise a hydrogen halide, such as HCl. In an embodiment, a co-catalystand/or a catalyst promoter may be fed to the modular reactor byinjection into the hydrocarbon feed, or by injection into the ionicliquid catalyst, or by direct injection into the modular reactor.

In an embodiment, the reactor effluent may be withdrawn from the base ofthe modular reactor via the circulation loop. Fresh ionic liquidcatalyst may be added to the withdrawn reactor effluent to provide therecirculation stream, and the recirculation stream may be cooled in thecirculation loop before introducing the cooled recirculation stream intothe first mixer module of the modular reactor. The reactor effluent maybe recirculated to the modular reactor without any attempt to separatethe reactor effluent within the circulation loop. As an example, in anembodiment the circulation loop may lack a separation unit or otherapparatus for phase separation of the reactor effluent or therecirculation stream. A portion of the withdrawn reactor effluent may beremoved from the circulation loop for fractionation to provide analkylate product.

In an embodiment, the flow rate through the circulation loop may be muchgreater than the total flow rate of the hydrocarbon feeds to reduce thetemperature rise in the modular reactor and to enhance the feed dilutionin the feed modules and mixer modules. In an embodiment, the flow ratethrough the circulation loop may be in the range from 2 to 50 times theflow rate of the hydrocarbon feed, or from 2 to 25 times the flow rateof the hydrocarbon feed, or from 4 to 10 times the flow rate of thehydrocarbon feed.

The step of mixing the recirculation stream via the first mixer modulemay comprise contacting the unreacted hydrocarbons with the ionic liquidcatalyst in the first mixer module under alkylation conditions toprovide an alkylate product. The step of mixing the hydrocarbon feedwith the ionic liquid/hydrocarbon emulsion via at least the second mixermodule may comprise contacting the hydrocarbon feed with the ionicliquid catalyst in at least the second mixer module under alkylationconditions to provide an additional amount of the alkylate product. Anyremaining unreacted hydrocarbons in at least the second mixer module mayalso be contacted with the ionic liquid catalyst under alkylationconditions to provide further quantities of the alkylate product. In anembodiment, each mixer module of the modular reactor may serve as anionic liquid alkylation zone. Furthermore, in an embodiment each feedmodule of the modular reactor may also serve as an ionic liquidalkylation zone.

In an embodiment, the first feed module may be disposed between thefirst and second mixer modules, such that the first feed module isdisposed downstream from the first mixer module and the second mixermodule is disposed downstream from the first feed module. Flow throughthe modular reactor may be downward, e.g., from the first mixer moduleto the first feed module and the second mixer module. The first feedmodule may be coaxial with both the first mixer module and the secondmixer module. In an embodiment, the modular reactor may compriseadditional mixer modules and additional feed modules. The mixer modulesmay be arranged alternately with the feed modules. Each feed module maybe disposed between two mixer modules such that when the number of mixermodules is n, the number of feed modules is (n−1), wherein n may be inthe range from two (2) to 10, or from two (2) to six (6), or from two(2) to four (4). In an embodiment, mixer modules of the modular reactor,e.g., the first mixer module and the second mixer module, may eachcomprise a static mixer. In an embodiment, at least one feed module ofthe modular reactor, e.g., the first feed module, may comprise asparger.

In an embodiment, the ionic liquid/hydrocarbon emulsion formed by mixingthe recirculation stream in the first mixer module may comprise small tomicroscopic droplets of the ionic liquid catalyst, e.g., having adroplet diameter in the range from 1 to 1000 microns, or from 5 to 500microns, or from 10 to 250 microns. Different combinations of staticmixer elements and liquid linear velocities may be chosen to achieve thesaid range of droplet size for the ionic liquid catalyst. For example,both helical type- and plate type static mixers that are able to producehigh turbulence and achieve good radial mixing may be used.

The system may be configured for distributing the hydrocarbon feed tothe modular reactor, e.g., via each feed module, between each adjacentpair of mixer modules. The second mixer module and any subsequent(downstream) mixer module(s) may be configured for thoroughly mixing thedistributed hydrocarbon feed with the mixed recirculation streamemanating from the first mixer module so as to maintain the ionic liquidcatalyst droplet diameter within the ranges cited hereinabove.

A range of the ionic liquid catalyzed hydrocarbon conversion processesmay be practiced using systems, apparatus, and processes as disclosedherein. As non-limiting examples, such hydrocarbon conversion processesmay include or be selected from: paraffin alkylation, paraffinisomerization, olefin oligomerization, cracking of olefins or paraffins,and aromatic alkylation.

In an embodiment of a process for ionic liquid catalyzed paraffinalkylation, the hydrocarbon feed may comprise at least one C₂-C₁₀ olefinand at least one C₄-C₁₀ isoparaffin. In an embodiment, the ionic liquidcatalyst may comprise a chloroaluminate ionic liquid. In an embodiment,the alkylation conditions may comprise a temperature in the range from−40° C. to 150° C., and a pressure in the range from atmosphericpressure to 8000 kPa. In an embodiment, the overall ionic liquidcatalyst volume in the modular reactor may be maintained in the rangefrom 0.5 to 50 vol %, or from 1 to 10 vol %, or from 2 to 6 vol %.Hydrocarbon feeds, ionic liquid catalysts, and conditions for ionicliquid catalyzed alkylation are described hereinbelow.

Systems and apparatus for ionic liquid catalyzed hydrocarbon conversion,including alkylation for gasoline production, will now be described withreference to the drawings.

FIG. 1A schematically represents a system for ionic liquid catalyzedhydrocarbon conversion processes. System 100 may comprise at least onemodular reactor 200 and at least one circulation loop 400. Modularreactor 200 provides for the rapid and thorough mixing of ionic liquidcatalyst and hydrocarbon reactants. As an example, modular reactor 200may generate a large surface area of the ionic liquid catalyst phase inan ionic liquid/hydrocarbon mixture, thereby providing for the highlyefficient performance of ionic liquid catalyzed hydrocarbon conversionprocesses.

Modular reactor 200 may have a reactor top 202 and a reactor base 203.In an embodiment, modular reactor 200 may be vertically aligned having aheight greater than its width. In an embodiment, modular reactor 200 maybe substantially cylindrical. In an embodiment, system 100 may comprisea plurality of mixer modules 210 per modular reactor 200 (see, forexample, FIGS. 2, 3, and 4A-4B). Circulation loop 400 may be in fluidcommunication with modular reactor 200 for withdrawing liquid (e.g.,reactor effluent) from modular reactor 200 into circulation loop 400.Circulation loop 400 may further be in fluid communication with modularreactor 200 for recirculating at least a portion of the withdrawn liquidto the reactor top 202 of modular reactor 200. Although only onecirculation loop 400 is shown in FIG. 1A, in an embodiment system 100may comprise a plurality of circulation loops 400 per modular reactor200, wherein each circulation loop 400 may be in fluid communicationwith modular reactor 200.

FIG. 1B schematically represents a system for ionic liquid catalyzedhydrocarbon conversion processes, wherein system 100 may comprise aplurality of modular reactors 200 per circulation loop 400. In anembodiment, the plurality of modular reactors 200 may be arranged inparallel. Each modular reactor 200 in the embodiment of FIG. 1B providesfor the rapid and thorough mixing of ionic liquid catalyst andhydrocarbon reactants, substantially as described with reference to FIG.1A, thereby providing for the highly efficient performance of ionicliquid catalyzed hydrocarbon conversion processes.

Each modular reactor 200 in the embodiment of FIG. 1B may have features,elements, and characteristics as described, for example, with referenceto FIGS. 1A, 2, 3, and 4A-4B. Although two modular reactors 200 areshown in FIG. 1B, larger numbers of modular reactors may also be usedper circulation loop 400. In an embodiment, the use of multiple modularreactors 200 per circulation loop 400 may serve to increase the overallreactor throughput. In an embodiment, reactor scale-up may beconveniently achieved by the addition of modular reactors 200 to system100.

FIG. 2 schematically represents a system 100 for ionic liquid catalyzedhydrocarbon conversion, wherein system 100 comprises a modular reactor200 and a circulation loop 400. Modular reactor 200 may comprise aplurality of mixer modules 210 and one or more feed modules 300. Eachmixer module 210 may be configured for mixing liquid(s), e.g.,comprising two or more immiscible liquids, flowing through modularreactor 200. Although three mixer modules 210 are shown in FIG. 2,modular reactor 200 may comprise other numbers of mixer modules 210(see, for example, FIG. 3).

Circulation loop 400 may comprise a first loop end 400 a coupled toreactor base 203 and a second loop end 400 b coupled to reactor top 202.Circulation loop 400 may further comprise a loop outlet 402, an ionicliquid catalyst inlet 404, a circulation pump 406, and a heat exchanger408. In embodiments having a plurality of circulation loops 400 permodular reactor 200, each circulation loop 400 may have a dedicatedcirculation pump 406 and heat exchanger 408.

System 100 may further comprise a feed supply line 302. Each feed module300 may include a feed conduit 304 in fluid communication with feedsupply line 302. In an embodiment, each feed module 300 may beconfigured for introducing a hydrocarbon feed 301 into modular reactor200, e.g., at an elevation between two adjacent, vertically stackedmixer modules 210. In an embodiment, each feed module 300 may beconfigured for uniformly distributing the hydrocarbon feed 301 over theentire cross-sectional area of modular reactor 200. In an embodiment,the hydrocarbon feed 301 may comprise an olefin feed stream, anisoparaffin feed stream, or a mixed olefin/isoparaffin feed, for ionicliquid catalyzed alkylation, e.g., as described hereinbelow. In anembodiment, the hydrocarbon feed 301 introduced into modular reactor 200may comprise a liquid feed.

System 100 may be configured for withdrawing reactor effluent 206 frombase 203 of modular reactor 200 into circulation loop 400. Reactoreffluent 206 may comprise ionic liquid catalyst that has previouslycontacted the hydrocarbon feed 301 in modular reactor 200. Fresh ionicliquid catalyst 403 may be added to reactor effluent 206, withincirculation loop 400, via ionic liquid catalyst inlet 404 to provide arecirculation stream 412. A portion of withdrawn reactor effluent 206may be removed from circulation loop 400, via loop outlet 402, e.g., forfractionation thereof to provide an alkylate product.

Although only one modular reactor 200 is shown in FIG. 2, in anembodiment a plurality of modular reactors 200 may be used percirculation loop 400 (see, for example, FIG. 1B). Loop outlet 402 andionic liquid catalyst inlet 404 may be disposed at various locationswithin circulation loop 400 other than as shown in FIG. 2. In anembodiment, system 100 may be configured for ionic liquid catalyzedalkylation reactions and processes. Feeds, ionic liquid catalysts, andreaction conditions for ionic liquid catalyzed alkylation are describedhereinbelow.

FIG. 3 schematically represents a modular reactor as seen from the side.Modular reactor 200 may have a reactor top 202 and a reactor base 203.Modular reactor 200 may be in fluid communication with a first loop end400 a and a second loop end 400 b of circulation loop 400 (see, forexample, FIG. 2). In an embodiment, modular reactor 200 may comprise aplurality of mixer modules 210 a-210 n and a plurality of feed modules300 a-300 n. Modular reactor 200 may receive recirculation stream 412 atthe first (uppermost) mixer module 210 a via second loop end 400 b.

In an embodiment, mixer modules 210 a-210 n may be arranged alternatelywith feed modules 300 a-300 n such that each feed module 300 is disposedbetween two mixer modules 210. In an embodiment, all mixer modules 210a-210 n and all feed modules 300 a-300 n may be arranged in series. Inan embodiment, each of modular reactor 200, mixer modules 210 a-210 n,and feed modules 300 a-300 n may be arranged vertically or upright. Inan embodiment, each mixer module 210 a-210 n and each feed module 300a-300 n may be vertically aligned, and each of mixer modules 210 a-210 nmay be arranged coaxially with each of feed modules 300 a-300 n.

In an embodiment, mixer modules 210 a-210 n and feed modules 300 a-300 nmay be stacked on top of each other, such that each mixer module 210a-210 n may be in contact (contiguous) with at least one of feed modules300 a-300 n, and each feed module 300 a-300 n may be in contact(contiguous) with two of mixer modules 210 a-210 n. In an embodiment,modular reactor 200 may have one more mixer module 210 than feed module300. As an example, for a modular reactor 200 having n mixer modules 210a-210 n, the number of feed modules 300 may be (n−1). In an embodiment,each modular reactor 200 may typically comprise from two (2) to 10 mixermodules 210, or from two (2) to six (6) mixer modules 210, or from two(2) to four (4) mixer modules 210.

FIG. 4A schematically represents components of a modular reactor inexploded view as seen from the side; FIG. 4B schematically represents amodular reactor as seen from the side; FIG. 4C schematically representsa modular reactor as seen along the line 4C-4C of FIG. 4B; and FIG. 4Dschematically represents a modular reactor as seen along the line 4D-4Dof FIG. 4B. With reference to FIGS. 4A-4D, modular reactor 200 maycomprise a plurality of vertically aligned mixer modules 210. Althoughtwo mixer modules 210 are shown in FIGS. 4A-4B, other numbers of mixermodules 210 may also be used (see, e.g., FIG. 3). In an embodiment, afeed module 300 may be disposed between each adjacent pair of mixermodules 210 such that when the number of mixer modules 210 is n, thenumber of feed modules 300 is (n−1).

In an embodiment, modular reactor 200 may be configured such that allmixer modules 210 and feed module(s) 300 are coaxial. A common axis ofmodular reactor 200, mixer modules 210, and feed module(s) 300 isindicated in FIG. 4A by the line labeled A_(MM)/A_(FM) (wherein themixer module axis and the feed module axis are designated as A_(MM) andA_(FM), respectively).

With further reference to FIGS. 4A-4D, in an embodiment each mixermodule 210 may include a mixer module housing 218 and each feed module300 may include a feed module housing 318. In an embodiment, each mixermodule 210 of modular reactor 200 may have a circular cross-section, andeach mixer module 210 may have the same or essentially the same internaldiameter, D_(MM). In an embodiment, each feed module 300 of modularreactor 200 may have a circular cross-section, and each feed module 300may have the same or essentially the same internal diameter, D_(FM). Ina sub-embodiment, the internal diameter, D_(MM), of each mixer module ofa given modular reactor 200 may be the same or essentially the same asthe internal diameter, D_(FM), of each feed module. In an embodiment,each mixer module 210 may occupy essentially the entire cross-sectionalarea of modular reactor 200.

Each mixer module 210 may have a mixer module proximal end 211 a and amixer module distal end 211 b. Each mixer module 210 may be configuredfor facile assembly to, and disassembly from, at least one feed module300; and each feed module 300 may be configured for facile assembly to,and disassembly from, two mixer modules 210. In an embodiment, eachmixer module 210 may comprise a mixer module proximal flange 212 a atthe mixer module proximal end 211 a and a mixer module distal flange 212b at the mixer module distal end 211 b.

In an embodiment, each feed module 300 may comprise a feed moduleproximal flange 312 a at the feed module proximal end 311 a and a feedmodule distal flange 312 b at the feed module distal end 311 b. Mixermodule distal flange 212 b may be configured for coupling to feed moduleproximal flange 312 a, such that mixer module distal end 211 b may beaffixed to the proximal end 311 a of an adjacent, downstream feed module300. In an embodiment, such affixation of mixer module distal end 211 bto feed module proximal end 311 a may be reversible. Feed module distalflange 312 b may be configured for coupling to mixer module proximalflange 212 a of an adjacent, downstream mixer module 210, e.g., suchthat feed module distal end 311 b may be reversibly affixed to mixermodule proximal end 211 a. Flanged couplings for pipes and cylindricalhousings comprising metal(s), plastics or other materials, and the likeare known in the art.

In an embodiment, at least one mixer module 210 of modular reactor 200may comprise a static mixer. In a sub-embodiment, each mixer module 210of modular reactor 200 may comprise a static mixer. In an embodiment,each mixer module 210 may comprise at least one mixer element disposedwithin mixer module housing 218 (see, for example, FIG. 5). Variousstatic mixers having a broad range of characteristics may be obtainedcommercially.

In an embodiment, mixer modules 210 for modular reactor 200 may beselected such that a total pressure drop across modular reactor 200,from reactor top 202 to reactor base 203, is in the range from 15 to 115psig, or from 20 to 100 psig. System 100 and modular reactor 200 may beconfigured to produce small to microscopic droplets of ionic liquidcatalyst within mixer modules 210 of modular reactor 200. In anembodiment, such droplets of ionic liquid catalyst may have a diameterin the range from 1 to 1000 microns, or from 5 to 500 microns, or from10 to 250 microns. Such droplets may provide not only an ionic liquidcatalyst surface area that will produce a high rate of reaction and ahigh quality product (e.g., alkylate), but also a hydrocarbon/ionicliquid mixed phase that is conducive to subsequent phase separationdownstream. The size or size range of ionic liquid droplets produced bymodular reactor 200 may be selected, for example, by adjusting the flowrate across modular reactor 200 and by mixer element design.

FIG. 5 schematically represents a modular reactor as seen from the side.Modular reactor 200 may have a reactor top 202 and a reactor base 203.In an embodiment, modular reactor 200 may comprise a first mixer module210 a, a second mixer module 210 b, and a third mixer module 210 c.Mixer modules 210 a-210 c may comprise mixer elements 220 a-220 c,respectively, disposed within mixer module housing 218. Such mixermodules 210 a-210 c comprising one or more mixer elements may bereferred to herein as static mixers. Static mixers may also be known asmotionless mixers. Systems and apparatus as disclosed herein are notlimited to any specific static mixer type, configuration, or design.

In an embodiment, mixer module housing 218 may comprise a cylindricalhousing. In an embodiment, each of mixer modules 210 a-210 c may have aseparate mixer module housing 218, and modular reactor 200 may beconfigured such that each of mixer modules 210 a-210 c may be removedseparately (see, for example, FIGS. 4A-4B). Such modular construction ofmodular reactor 200 allows for the facile assembly and disassembly ofmodular reactor 200. Mixer modules 210 a-210 c may additionally includevarious elements, features and characteristics as described herein, forexample, with reference to FIGS. 3 and 4A-4D.

With further reference to FIG. 5, modular reactor 200 may be in fluidcommunication with first loop end 400 a of circulation loop 400 atreactor base 203 for withdrawing reactor effluent from modular reactor200. Modular reactor 200 may further be in fluid communication withsecond loop end 400 b of circulation loop 400 at reactor top 202 fordelivering recirculation stream 412 to modular reactor 200. First mixermodule 210 a may be coaxial with second mixer module 210 b and thirdmixer module 210 c.

With still further reference to FIG. 5, a first feed module 300 a may bedisposed between first and second mixer modules, 210 a and 210 b,respectively, such that first feed module 300 a is disposed downstreamfrom, and in fluid communication with, first mixer module 210 a. Secondmixer module 210 b may be disposed downstream from, and in fluidcommunication with, first feed module 300 a. First feed module 300 a maybe configured for distributing hydrocarbon feed between first mixermodule 210 a and second mixer module 210 b. First feed module 300 a maybe reversibly affixed to, and in contact (contiguous) with, each offirst mixer module 210 a and second mixer module 210 b.

A second feed module 300 b may be disposed between second and thirdmixer modules, 210 b and 210 c, respectively, such that second feedmodule 300 b is disposed downstream from, and in fluid communicationwith, second mixer module 210 b. Third mixer module 210 c may bedisposed downstream from, and in fluid communication with, second feedmodule 300 b. First mixer module 210 a may be coaxial with first feedmodule 300 a and second feed module 300 b. Second feed module 300 b maybe configured for distributing hydrocarbon feed between second mixermodule 210 b and third mixer module 210 c. Second feed module 300 b maybe reversibly affixed to, and in contact with, each of second mixermodule 210 b and third mixer module 210 c.

First feed module 300 a and second feed module 300 b may comprise afirst feed conduit 304 a and a second feed conduit 304 b, respectively.First feed module 300 a and second feed module 300 b may furthercomprise a first sparger 320 a and a second sparger 320 b, respectively.First sparger 320 a and second sparger 320 b may be in fluidcommunication with first feed conduit 304 a and second feed conduit 304b, respectively. Each of first feed conduit 304 a and second feedconduit 304 b may be in fluid communication with feed supply line 302(see, for example, FIG. 2) for providing hydrocarbon feed to modularreactor 200. Although, FIG. 5 shows three mixer modules 210 a-210 c andtwo feed modules 300 a, 300 b, other numbers of mixer modules and feedmodules are also possible (see, for example, FIG. 3).

FIGS. 6A and 6B each schematically represents a sparger, as seen inreverse plan view, for distributing hydrocarbon feed 301 to a modularreactor 200. FIG. 6A schematically represents a tree sparger 320′ incombination with a feed conduit 304. FIG. 6B schematically represents aring sparger 320″ in combination with a feed conduit 304. In anembodiment, one or more feed modules 300 of modular reactor 200 (e.g.,feed modules 300 a-300 n, FIG. 3) may each comprise tree sparger 320′ orring sparger 320″.

Feed conduit 304 may be in fluid communication with spargers 320′/320″and with feed supply line 302 (see, e.g., FIG. 2) for providinghydrocarbon feed 301 to spargers 320′/320″. Each of spargers 320′/320″may be configured for distributing hydrocarbon feed 301 at a locationupstream from an adjacent downstream mixer module 210 (see, for example,FIG. 5). In an embodiment, spargers 320′/320″ may be configured foruniformly distributing the hydrocarbon feed over the entirecross-sectional area of modular reactor 200. In an embodiment, spargers320′/320″ may have a circular cross-section and a diameter D_(S). In anembodiment, the diameter, D_(S), of spargers 320′/320″ may be in therange from 40 to 100% of the mixer module internal diameter, D_(MM), orfrom 60 to 100% of the mixer module internal diameter, D_(MM), or from90 to 99% of the mixer module internal diameter, D_(MM). In anembodiment, the mixer module internal diameter, D_(MM), may be the sameor essentially the same as the feed module internal diameter, D_(FM).

In an embodiment, system 100 as disclosed herein may be used for ionicliquid catalyzed alkylation processes. In an embodiment, the ionicliquid catalyst may comprise, e.g., a chloroaluminate ionic liquid asdescribed hereinbelow. In an embodiment, the hydrocarbon feed maycomprise at least one of an olefin feed stream, an isoparaffin feedstream, and a mixed olefin/isoparaffin feed, for ionic liquid catalyzedalkylation, e.g., as also described hereinbelow.

FIG. 7 schematically represents a system and process for ionic liquidcatalyzed hydrocarbon conversion, according to another embodiment.System 100′ of FIG. 7 may comprise a modular reactor 200 having areactor top 202, a reactor base 203, and a reactor outlet 204. Modularreactor 200 may comprise a plurality of mixer modules and one or morefeed modules (see, for example, FIGS. 3-5). System 100′ may haveelements and features in common with system 100 (see, for example, FIGS.1A-1B and 2). In modular reactor 200, at least one isoparaffin and atleast one olefin may be contacted with ionic liquid catalyst under ionicliquid alkylation conditions. Ionic liquid alkylation conditions,feedstocks, and ionic liquid catalysts that may be suitable forperforming ionic liquid alkylation reactions are described, for example,hereinbelow.

In an embodiment, a process for ionic liquid catalyzed hydrocarbonconversion may include adding a co-catalyst, or a catalyst promoter, orboth a catalyst promoter and a co-catalyst, to modular reactor 200. Inan embodiment, such a co-catalyst may comprise an alkyl chloride. Acatalyst promoter for addition to the modular reactor may comprise ahydrogen halide, such as HCl. In an embodiment, a co-catalyst and/or acatalyst promoter may be fed to modular reactor 200 via the hydrocarbonfeed, or via the ionic liquid catalyst feed, or by separate directinjection into modular reactor 200. The addition of co-catalyst(s)and/or catalyst promoter(s) to modular reactor 200 is not shown in theDrawings. Various methods and techniques for introducing co-catalyst(s)and/or catalyst promoter(s) to modular reactor 200 will be apparent tothe skilled artisan.

System 100′ may further comprise a circulation loop 400. Circulationloop 400 may comprise a first loop end 400 a coupled to vessel outlet204 and a second loop end 400 b coupled to reactor top 202. In anembodiment, a first mixer module 210 a may be disposed at reactor top202 (see, for example, FIG. 3), and second loop end 400 b may be coupledto, and in fluid communication with, first mixer module 210 a.Circulation loop 400 may further comprise a circulation pump 406, and aheat exchanger 408. Circulation loop 400 may still further comprise atleast one circulation loop conduit 410, e.g., for coupling components ofcirculation loop 400 to vessel outlet 204 and reactor top 202.

System 100′ may still further comprise an ionic liquid/hydrocarbon(IL/HC) separator 500 in fluid communication with circulation loop 400,and a fractionation unit 600 in fluid communication with IL/HC separator500. Reactor effluent 206 may be withdrawn from modular reactor 200 intocirculation loop 400 via vessel outlet 204. A portion of the reactoreffluent 206 may be fed from circulation loop 400, via a line 501, toIL/HC separator 500 for separation of the portion of reactor effluentinto a hydrocarbon phase 502 and an ionic liquid phase 403′.Non-limiting examples of separation processes that can be used for suchphase separation include coalescence, phase separation, extraction,membrane separation, and partial condensation. IL/HC separator 500 maycomprise, for example, one or more of the following: a settler, acoalescer, a centrifuge, a cyclone, a distillation column, a condenser,and a filter. In an embodiment, IL/HC separator 500 may comprise agravity based settler and a coalescer disposed downstream from thegravity based settler.

It can be seen from FIG. 7 that IL/HC separator 500 may be external tocirculation loop 400. In an embodiment, circulation loop 400 may lack aunit or apparatus for phase separation of reactor effluent 206 or theexternal recirculation stream, R_(E). Accordingly, reactor effluent 206may be recirculated to modular reactor 200 without any attempt toseparate reactor effluent 206, or the external recirculation stream,within circulation loop 400. System 100′ having IL/HC separator 500external to circulation loop 400 allows IL/HC separator 500 to besmaller than that for a system in which a separator may be used forphase separation of 100% of the withdrawn reactor effluent within ahydrocarbon recycle loop.

The hydrocarbon phase 502 from IL/HC separator 500 may be fed via a line503 to fractionation unit 600. The hydrocarbon phase from IL/HCseparator 500 may comprise alkylate components (product), as well asunreacted components of hydrocarbon feed 301, including isobutane. Thealkylate components may comprise, e.g., C₅-C₁₁ alkanes, such as C₇-C₈isoparaffins. The hydrocarbon phase from IL/HC separator 500 may befractionated via fractionation unit 600 to provide one or more products602 a-n and an isobutane fraction. In an embodiment, products 602 a-nmay comprise alkylate, n-butane, and propane. In an embodiment,fractionation unit 600 may comprise one or more distillation columns.

At least a portion of the isobutane stream from fractionation unit 600may be recycled via a line 604 to modular reactor 200. In an embodiment,the recycle isobutane may be premixed with at least one of an olefinfeed stream 301 a and a make-up isobutane feed stream 301 b to provide amixed hydrocarbon feed 301 for introduction into modular reactor 200. Inan embodiment, modular reactor 200 may comprise a plurality of feedmodules, and each feed module may separately receive hydrocarbon feed301, e.g., via their respective feed conduit 304 (see, for example, FIG.5). Although two inputs for hydrocarbon feed 301 to modular reactor 200are shown in FIG. 7, other numbers and configurations are possible. Inan embodiment, the number of feed modules per modular reactor 200 may bein the range from one (1) to 9, or from one (1) to five (5), or from one(1) to three (3).

The ionic liquid phase 403′ from IL/HC separator 500 may be recycled tocirculation loop 400 via a line 505. Make-up (e.g., fresh) ionic liquidcatalyst 403 may be combined with the recycled ionic liquid catalyst viaa line 509. The combined fresh and recycled ionic liquid catalyst may beinjected into the reactor effluent within circulation loop 400 toprovide an external recirculation stream, R_(E), which may be cooled viaheat exchanger 408. The cooled external recirculation stream may berecirculated to modular reactor 200 via circulation loop 400. In anembodiment, the ionic liquid catalyst may be added to system 100′ at arate sufficient to maintain the overall ionic liquid catalyst volume inmodular reactor 200 in the range from 0.5 to 50 vol %, or from 1 to 10vol %, or from 2 to 6 vol %.

In an embodiment, the ionic liquid phase 403′ may be recycled tocirculation loop 400 either directly or indirectly through a catalystsurge vessel (the latter not shown). In an embodiment, a portion of theionic liquid phase 403′ from IL/HC separator 500 may be purged orwithdrawn to other vessels (not shown), via a line 507, for ionic liquidcatalyst regeneration, e.g., as described hereinbelow.

Feedstocks for Ionic Liquid Catalyzed Alkylation

In an embodiment, feedstocks for ionic liquid catalyzed alkylation maycomprise various olefin- and isoparaffin containing hydrocarbon streamsin or from one or more of the following: a petroleum refinery, agas-to-liquid conversion plant, a coal-to-liquid conversion plant, anaphtha cracker, a middle distillate cracker, a natural gas productionunit, a LPG production unit, and a wax cracker, and the like.

Examples of olefin containing streams include FCC off-gas, coker gas,olefin metathesis unit off-gas, polyolefin gasoline unit off-gas,methanol to olefin unit off-gas, FCC light naphtha, coker light naphtha,Fischer-Tropsch unit condensate, and cracked naphtha. Some olefincontaining feed streams may contain at least one olefin selected fromethylene, propylene, butylenes, pentenes, and up to C₁₀ olefins, i.e.,C₂-C₁₀ olefins, and mixtures thereof. Such olefin containing streams arefurther described, for example, in U.S. Pat. No. 7,572,943, thedisclosure of which is incorporated by reference herein in its entirety.

Examples of isoparaffin containing streams include, but are not limitedto, FCC naphtha, hydrocracker naphtha, coker naphtha, Fisher-Tropschunit condensate, natural gas condensate, and cracked naphtha. Suchstreams may comprise at least one C₄-C₁₀ isoparaffin. In an embodiment,such streams may comprise a mixture of two or more isoparaffins. In asub-embodiment, an isoparaffin feed to the alkylation reactor during anionic liquid catalyzed alkylation process may comprise isobutane.

Paraffin Alkylation

In an embodiment, the alkylation of a mixture of hydrocarbons may beperformed in a modular reactor vessel under conditions known to producealkylate gasoline. The modular reactor may be referred to herein as analkylation reactor, and the modular reactor may comprise at least onealkylation zone. The alkylation conditions in the alkylation reactor areselected to provide the desired product yields and quality. Thealkylation reaction in the alkylation reactor is generally carried outin a liquid hydrocarbon phase, in a batch system, a semi-batch system,or a continuous system. The catalyst volume in the alkylation reactormay be in the range of 0.5 to 50 vol %, or from 1 to 20 vol %, or from 2to 6 vol %. In an embodiment, vigorous mixing can be attained by usingone or more mixing devices per reactor, e.g., as described hereinabove,to provide contact between the hydrocarbon reactants and ionic liquidcatalyst over a large surface area per unit volume of the reactor. Thealkylation reaction temperature can be in the range from −40° C. to 150°C., such as −20° C. to 100° C., or −15° C. to 50° C. The alkylationpressure can be in the range from atmospheric pressure to 8000 kPa. Inan embodiment the alkylation pressure is maintained at a level at leastsufficient to keep the reactants in the liquid phase. The residence timeof reactants in the reactor can be in the range of a second to 60 hours.

In one embodiment, the molar ratio of isoparaffin to olefin in thealkylation reactor can vary over a broad range. Generally the molarratio of isoparaffin to olefin is in the range of from 0.5:1 to 100:1.For example, in different embodiments the molar ratio of isoparaffin toolefin is from 1:1 to 50:1, from 1.1:1 to 10:1, or from 1.1:1 to 20:1.Lower isoparaffin to olefin molar ratios will tend to produce a higheryield of higher molecular weight alkylate products, and thus can beselected when operating the alkylation reactor in a distillate mode,such as described in U.S. Patent Publication No. US20110230692A1.

Other Hydrocarbon Conversion Processes

Systems comprising a modular reactor as disclosed herein can be used forother hydrocarbon conversion processes using an acidic ionic liquidcatalyst. Some examples of the hydrocarbon conversion processes includeisomerization of C₄-C₈ paraffin where normal paraffins are converted toisoparaffins, oligomerization of C₃-C₃₀ olefins to produce highermolecular weight olefins, isomerization of C₃-C₃₀ olefins to shift thelocation of the double bond in the molecule (double bond isomerization)or shift the back-bone of the olefin molecules (skeletal isomerization),cracking of high molecular weight olefins and paraffins to low molecularparaffins and olefins, and alkylation of olefins with aromatics to formalkylaromatics.

Ionic Liquid Catalysts for Hydrocarbon Conversion Processes

In an embodiment, a catalyst for hydrocarbon conversion processes may bea chloride-containing ionic liquid catalyst comprised of at least twocomponents which form a complex. A first component of thechloride-containing ionic liquid catalyst can comprise a Lewis Acidselected from components such as Lewis Acidic compounds of Group 13metals, including aluminum halides, alkyl aluminum halides, galliumhalides, and alkyl gallium halides, indium halides, and alkyl indiumhalides (see International Union of Pure and Applied Chemistry (IUPAC),version 3, October 2005, for Group 13 metals of the periodic table).Other Lewis Acidic compounds, in addition to those of Group 13 metals,can also be used. In one embodiment the first component is aluminumhalide or alkyl aluminum halide. For example, aluminum trichloride canbe the first component of the chloride-containing ionic liquid catalyst.

A second component comprising the chloride-containing ionic liquidcatalyst is an organic salt or mixture of salts. These salts can becharacterized by the general formula Q⁺A⁻ wherein Q⁺ is an ammonium,phosphonium, boronium, iodonium, or sulfonium cation and A⁻ is anegatively charged ion such as Cl⁻, Br⁻, ClO₄ ⁻, NO₃ ⁻, BF₄ ⁻, BCl₄ ⁻,PF₆ ⁻, SbF₆ ⁻, AlCl₄ ⁻, TaF₆ ⁻, CuCl₂ ⁻, FeCl₃ ⁻, HSO₃ ⁻, RSO₃ ⁻(wherein R is an alkyl group having from 1 to 12 carbon atoms), SO₃CF₃⁻, and 3-sulfurtrioxyphenyl. In one embodiment, the second component isselected from those having quaternary ammonium or phosphonium halidescontaining one or more alkyl moieties having from 1 to 12 carbon atoms,such as, for example, trimethylamine hydrochloride,methyltributylammonium halide, trialkylphosphonium hydrochloride,tetraalkylphosphonium chlorides, methyltrialkylphosphonium halide orsubstituted heterocyclic ammonium halide compounds, such as hydrocarbylsubstituted pyridinium halide compounds, for example, 1-butylpyridiniumhalide, benzylpyridinium halide, or hydrocarbyl substituted imidazoliumhalides, such as for example, 1-ethyl-3-methyl-imidazolium chloride.

In one embodiment the chloride-containing ionic liquid catalyst isselected from the group consisting of hydrocarbyl substituted pyridiniumchloroaluminate, hydrocarbyl substituted imidazolium chloroaluminate,quaternary amine chloroaluminate, trialkyl amine hydrogen chloridechloroaluminate, alkyl pyridine hydrogen chloride chloroaluminate, andmixtures thereof. For example, the chloride-containing ionic liquidcatalyst can be an acidic haloaluminate ionic liquid, such as an alkylsubstituted pyridinium chloroaluminate or an alkyl substitutedimidazolium chloroaluminate of the general formulas A and B,respectively.

In the formulas A and B, R, R₁, R₂, and R₃ are H, methyl, ethyl, propyl,butyl, pentyl or hexyl group, and X is a chloroaluminate. In theformulas A and B, R, R₁, R₂, and R₃ may or may not be the same. In oneembodiment the chloride-containing ionic liquid catalyst isN-butylpyridinium chloroaluminate. Examples of highly acidicchloroaluminates are Al₂Cl₇ ⁻ and Al₃Cl₁₀ ⁻.

In another embodiment the chloride-containing ionic liquid catalyst canhave the general formula RR′R″NH⁺ Al₂Cl₇ ⁻ wherein R, R′, and R″ arealkyl groups containing from 1 to 12 carbons, and where R, R′, and R″may or may not be the same.

In another embodiment the chloride-containing ionic liquid catalyst canhave the general formula RR′R″R′″P⁺ Al₂Cl₇ ⁻ wherein R, R′, R″ and R′″are alkyl groups containing from 1 to 12 carbons, and where R, R′, R″and R′″ may or may not be the same.

The presence of the first component should give the chloride-containingionic liquid a Lewis or Franklin acidic character. Generally, thegreater the mole ratio of the first component to the second component,the greater is the acidity of the chloride-containing ionic liquidcatalyst. The molar ratio of the first component (metal halide) to thesecond component (quaternary amine or quaternary phosphorus) is in therange of 2:1 to 1.1:1.

In one embodiment, the chloride-containing ionic liquid catalyst ismixed in the alkylation reactor with a hydrogen halide and/or an organichalide. The hydrogen halide or organic halide can boost the overallacidity and change the selectivity of the chloride-containing ionicliquid catalyst. The organic halide can be an alkyl halide. The alkylhalides that can be used include alkyl bromides, alkyl chlorides, alkyliodides, and mixtures thereof. A variety of alkyl halides can be used.Alkyl halide derivatives of the isoparaffins or the olefins thatcomprise the feed streams in the alkylation process are good choices.Such alkyl halides include, but are not limited to, isopentyl halides,isobutyl halides, butyl halides (e.g., 1-butyl halide or 2-butylhalide), propyl halides and ethyl halides. Other alkyl chlorides orhalides having from 1 to 8 carbon atoms can be also used. The alkylhalides can be used alone or in combination or with hydrogen halide. Thealkyl halide or hydrogen halide is fed to the unit by injecting thealkyl halide or hydrogen halide to the hydrocarbon feed, or to the ionicliquid catalyst or to the alkylation reactor directly. The amount of HClor alkyl chloride usage, the location of the injection and the injectionmethod may affect the amount of organic chloride side-product formation.The use of alkyl halides to promote hydrocarbon conversion bychloride-containing ionic liquid catalysts is taught in U.S. Pat. No.7,495,144 and in U.S. Patent Publication No. 20100298620A1.

It is believed that the alkyl halide decomposes under hydrocarbonconversion conditions to liberate Bronsted acids or hydrogen halides,such as hydrochloric acid (HCl) or hydrobromic acid (HBr). TheseBronsted acids or hydrogen halides promote the hydrocarbon conversionreaction. In one embodiment the halide in the hydrogen halide or alkylhalide is chloride. In one embodiment the alkyl halide is an alkylchloride, for example t-butyl chloride. Hydrogen chloride and/or analkyl chloride can be used advantageously, for example, when thechloride-containing ionic liquid catalyst is a chloroaluminate.

Ionic Liquid Catalyst Regeneration

As a result of use, ionic liquid catalysts become deactivated, i.e. loseactivity, and may eventually need to be replaced. However, ionic liquidcatalysts are expensive and replacement adds significantly to operatingexpenses. Thus it is desirable to regenerate the ionic liquid catalyston-line and reuse in the alkylation process. The regeneration of acidicionic liquid catalysts is taught in U.S. Pat. No. 7,651,970, U.S. Pat.No. 7,674,739, U.S. Pat. No. 7,691,771, U.S. Pat. No. 7,732,363, andU.S. Pat. No. 7,732,364.

Alkylation processes utilizing an ionic liquid catalyst form by-productsknown as conjunct polymers. These conjunct polymers are highlyunsaturated molecules and deactivate the ionic liquid catalyst byforming complexes with the ionic liquid catalyst. A portion of usedionic liquid catalyst from the alkylation reactor is sent to theregenerator reactor which removes the conjunct polymer from the ionicliquid catalyst and recovers the activity of the ionic liquid catalyst.The regeneration reactor contains metal components that saturates theconjunct polymers and releases the saturated polymer molecules from theionic liquid catalyst. The regeneration can be performed either in astirred reactor or a fixed bed reactor. For ease of operation, a fixedbed reactor is preferred even though the fixed bed regenerator reactoris more susceptible to plugging from coking, deposits of corrosionproducts and decomposition products derived from feed contaminants. Aguard bed vessel containing adsorbent material with appropriate poresize may be added before the regeneration reactor to minimizecontaminants going into the regeneration reactor.

Product Separation and Finishing

The hydrocarbon effluent product from the reactor containing ionicliquid catalyst and hydrogen halide co-catalyst may contain traceamounts of hydrogen halides or organic halides or inorganic halides.When aluminum chloride containing catalyst is used, then trace amountsof HCl, organic chlorides and inorganic chlorides may be present in thereactor effluent. HCl and organic chlorides are preferred to be capturedand recycled to the alkylation reactor. Inorganic chlorides such ascorrosion products or decomposition product may be captured with afilter.

The separated hydrocarbon product may still contain trace amounts ofHCl, organic chlorides and inorganic chlorides. Removal of HCl andinorganic chlorides from the product are typically done by causticwashing. Chloride selective adsorbent may be used to capture theresidual chlorides. Organic chloride may be converted to HCl and organichydrocarbon by hydrogenation, cracking or hot caustic treating. Treatingof products for chloride reduction is taught, for example, in U.S. Pat.No. 7,538,256, U.S. Pat. No. 7,955,498, and U.S. Pat. No. 8,327,004.

EXAMPLES Example 1

N-butylpyridinium chloroaluminate (C₅H₅NC₄H₉Al₂Cl₇) ionic liquidcatalyst (1:2 molar ratio of N-butyl pyridinium chloride and AlCl₃) wasused to produce alkylate shown in Example 2. The acidic ionic liquidcatalyst had aluminum chloride as a metal halide component. The catalysthad the following elemental composition.

Wt % Al 12.4 Wt % Cl 56.5 Wt % C 24.6 Wt % H 3.2 Wt % N 3.3

Example 2

The acidic ionic liquid catalyst described in Example 1 was used toalkylate C₃-C₄ olefins with isobutane in a process unit. The alkylationwas performed in a static mixer reactor system containing three mixermodules and two feed modules arranged in the sequence shown in FIG. 2.Each feed module had three spargers for hydrocarbon feed introduction.An 18:1 molar ratio of isobutane to total olefin mixture was fed to thereactor via the two feed modules. Reactor effluent was withdrawn fromthe base of the reactor and recirculated to the top of the reactor via acirculation loop containing the recycle flow). The relative rate of therecycle flow to the fresh hydrocarbon feed was 17:1. The pressure dropacross the reactor was 50 psi. The acidic ionic liquid catalyst was fedto the circulation loop to occupy 7 vol % in the reactor. A small amountof anhydrous n-butyl chloride corresponding to 120:1 molar ratio ofolefin to n-butyl chloride was added to the acidic ionic liquid catalystin the reactor. The average residence time of the combined feeds(isobutane/olefin mixture and catalyst) in the reactor and loop wasabout four minutes. The outlet pressure was maintained at 190 psig andthe reactor temperature was maintained at 35° C. (95° F.) using externalcooling. The reactor effluent was separated with a coalescing separatorinto a hydrocarbon phase and an acidic ionic liquid catalyst phase.

The bulk of the separated ionic liquid catalyst was recycled back to thealkylation reactor through the circulation loop. A portion of theseparated acidic ionic liquid catalyst phase was sent to a catalystregeneration unit to maintain the conjunct polymer level in thealkylation catalyst in the range from 3 to 5 wt %.

The hydrocarbon phase was then sent to a series of three distillationcolumns to separate C₅ ⁺, n-butane, C₃ ⁻ offgas and isobutene recyclestreams. The C₅ ⁺ alkylate stream was analyzed using D86 laboratorydistillation. Research and Motor Octane numbers were measured with anengine test. ASTM D86 distillation of the C₅ ⁺ stream showed the initialboiling point of 102° F. (39 degree Celsius), T₅₀ boiling point of 213°F. (101 degree Celsius), T₉₀ boiling point of 346° F. (174 degreeCelsius) and the end boiling point of 433° F. (223 degree Celsius). Theresulting C₅ stream was an alkylate gasoline having a 89 RON and 89 MON.These results indicate that the in-line mixer reactor can produce highquality alkylate gasoline that can be readily blended to the refinerygasoline pool.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Furthermore, all ranges disclosed herein are inclusive ofthe endpoints and are independently combinable. Whenever a numericalrange with a lower limit and an upper limit are disclosed, any numberfalling within the range is also specifically disclosed.

Any term, abbreviation or shorthand not defined is understood to havethe ordinary meaning used by a person skilled in the art at the time theapplication is filed. The singular forms “a,” “an,” and “the,” includeplural references unless expressly and unequivocally limited to oneinstance.

All of the publications, patents and patent applications cited in thisapplication are herein incorporated by reference in their entirety tothe same extent as if the disclosure of each individual publication,patent application or patent was specifically and individually indicatedto be incorporated by reference in its entirety.

The drawings are representational and may not be drawn to scale.Modifications of the exemplary embodiments disclosed above may beapparent to those skilled in the art in light of this disclosure.Accordingly, the invention is to be construed as including all structureand methods that fall within the scope of the appended claims. Unlessotherwise specified, the recitation of a genus of elements, materials orother components, from which an individual component or mixture ofcomponents can be selected, is intended to include all possiblesub-generic combinations of the listed components and mixtures thereof.

What is claimed is:
 1. A system for ionic liquid catalyzed hydrocarbon conversion, the system comprising: a modular reactor comprising a plurality of static mixer modules and one or more feed modules, wherein: said static mixer modules are arranged in series, each said static mixer module and each said feed module is vertically aligned, said static mixer modules are arranged alternately with said feed modules such that each feed module is disposed between two of said static mixer modules, and each said static mixer module is arranged coaxially with each said feed module.
 2. The system according to claim 1, wherein the number of said static mixer modules is n, and the number of said feed modules is (n−1).
 3. The system according to claim 2, wherein the number of said static mixer modules, n, is in the range from two (2) to
 10. 4. The system according to claim 1, wherein: each said static mixer module is in contact with at least one of said feed modules, and each said feed module is in contact with two of said static mixer modules.
 5. The system according to claim 1, wherein: each said static mixer module and each said feed module has a circular cross-section, and each said static mixer module and each said feed module has the same internal diameter.
 6. The system according to claim 1, wherein each said static mixer module occupies essentially the entire cross-sectional area of the modular reactor.
 7. The system according to claim 1, further comprising a feed supply line, wherein: each said feed module includes a feed conduit, each said feed conduit is in fluid communication with the feed supply line, and the system is configured for delivering hydrocarbon feed to the modular reactor via each said feed module.
 8. The system according to claim 1, wherein each said feed module comprises a sparger.
 9. (canceled)
 10. The system according to claim 1, wherein: each said static mixer module has a static mixer module proximal end and a static mixer module distal end, and each said static mixer module comprises a static mixer module proximal flange at the static mixer module proximal end and a static mixer module distal flange at the static mixer module distal end, each said feed module has a feed module proximal end and a feed module distal end, each said feed module comprises a feed module proximal flange at the feed module proximal end and a feed module distal flange at the feed module distal end, the static mixer module distal flange is configured for coupling to the feed module proximal flange, and the feed module distal flange is configured for coupling to the static mixer module proximal flange.
 11. The system according to claim 1, further comprising: a circulation loop in fluid communication with the modular reactor, the modular reactor having a base and a top, the circulation loop having a first loop end coupled to the base of the modular reactor, and the circulation loop further having a second loop end coupled to the top of the modular reactor, the system configured for withdrawing reactor effluent from the modular reactor via the first loop end into the circulation loop, and the system further configured for delivering a recirculation stream to the top of the modular reactor via the second loop end, wherein the circulation loop comprises: an ionic liquid catalyst inlet configured for adding fresh ionic liquid catalyst to withdrawn reactor effluent to provide the recirculation stream, and a heat exchanger configured for cooling the recirculation stream.
 12. The system according to claim 1, additionally comprising: a feed supply line in fluid communication with each said feed module.
 13. The system according to claim 12, wherein: each said feed module includes a feed conduit, each said feed conduit is in fluid communication with the feed supply line, and the system is configured for delivering hydrocarbon feed to the modular reactor via each said feed module.
 14. The system according to claim 12, wherein: each said static mixer module is in fluid communication with, and in contact with, at least one of said feed modules, and each said feed module is in fluid communication with, and reversibly affixed to, two of said static mixer modules.
 15. The system according to claim 12, wherein: each said feed module comprises a sparger.
 16. The system according to claim 13, further comprising: a circulation loop in fluid communication with the modular reactor, the modular reactor having a base and a top, the circulation loop having a first loop end coupled to the base of the modular reactor, and the circulation loop further having a second loop end coupled to the top of the modular reactor, the system configured for withdrawing reactor effluent from the modular reactor via the first loop end into the circulation loop, wherein the circulation loop comprises: an ionic liquid catalyst inlet configured for adding fresh ionic liquid catalyst to withdrawn reactor effluent to provide a recirculation stream, and a heat exchanger configured for cooling the recirculation stream.
 17. The system according to claim 16, wherein: the plurality of static mixer modules comprise a first static mixer module and at least a second static mixer module disposed downstream from the first static mixer module, the first static mixer module is in fluid communication with the second loop end for receiving the recirculation stream from the circulation loop, the first static mixer module is configured for mixing the recirculation stream, and the second static mixer module is configured for mixing the hydrocarbon feed with the recirculation stream.
 18. A system for ionic liquid catalyzed hydrocarbon conversion, the system comprising: a modular reactor having a base and a top; and a circulation loop in fluid communication with the modular reactor, the circulation loop having a first loop end coupled to the base of the modular reactor, the system configured for withdrawing reactor effluent from the base of the modular reactor into the circulation loop, the circulation loop further having a second loop end coupled to the top of the modular reactor, and the system further configured for delivering a recirculation stream to the top of the modular reactor; wherein the modular reactor comprises: a first static mixer, a first feed module comprising a sparger, disposed downstream from, and in fluid communication with, the first static mixer, and a second static mixer disposed downstream from, and in fluid communication with, the first feed module, wherein the first static mixer is coaxial with the first feed module and the second static mixer.
 19. The system according to claim 18, wherein the modular reactor further comprises: a second feed module disposed downstream from, and in fluid communication with, the second static mixer, and a third static mixer disposed downstream from, and in fluid communication with, the second feed module, wherein: the first feed module is reversibly affixed to, and in contact with, each of the first static mixer and the second static mixer, the first static mixer is coaxial with the second feed module and the third static mixer, and the second feed module is reversibly affixed to, and in contact with, each of the second static mixer and the third static mixer.
 20. The system according to claim 19, wherein: the first feed module is configured for distributing hydrocarbon feed between the first static mixer and the second static mixer, and the second feed module is configured for distributing hydrocarbon feed between the second static mixer and the third static mixer.
 21. A process for ionic liquid catalyzed hydrocarbon conversion, comprising: a) withdrawing reactor effluent from a modular reactor, the reactor effluent comprising unreacted hydrocarbons from a hydrocarbon feed; b) adding ionic liquid catalyst to the reactor effluent to provide a recirculation stream; c) introducing the recirculation stream into a first static mixer module of the modular reactor; d) via the first static mixer module, mixing the recirculation stream to provide an ionic liquid/hydrocarbon emulsion comprising the ionic liquid catalyst and the unreacted hydrocarbons; e) via a first feed module, distributing the hydrocarbon feed at an elevation between the first static mixer module and at least a second static mixer module disposed downstream from the first static mixer module; and f) via at least the second static mixer module, mixing the hydrocarbon feed with the ionic liquid/hydrocarbon emulsion.
 22. The process according to claim 21, wherein step d) comprises contacting the unreacted hydrocarbons with the ionic liquid catalyst in the first static mixer module under alkylation conditions to provide an alkylate product.
 23. The process according to claim 22, wherein step f) comprises contacting the hydrocarbon feed with the ionic liquid catalyst in at least the second static mixer module under alkylation conditions to provide an additional amount of the alkylate product.
 24. The process according to claim 21, wherein each of the first static mixer module and the second static mixer module comprises a static mixer that is a helical type- or a plate type-static mixer that produces high turbulence and good radial mixing.
 25. The process according to claim 21, wherein: the first feed module is disposed downstream from the first static mixer module, the second static mixer module is disposed downstream from the first feed module, and the first feed module is coaxial with both the first static mixer module and the second static mixer module.
 26. The process according to claim 21, wherein the first feed module comprises a sparger.
 27. The process according to claim 23, wherein: the ionic liquid catalyzed hydrocarbon conversion comprises paraffin alkylation, the hydrocarbon feed comprises at least one C₂-C₁₀ olefin and at least one C₄-C₁₀ isoparaffin, the ionic liquid catalyst comprises a chloroaluminate ionic liquid, and the alkylation conditions comprise a temperature in the range from −40° C. to 150° C., and a pressure in the range from atmospheric pressure to 8000 kPa.
 28. The process according to claim 21, wherein the ionic liquid/hydrocarbon emulsion comprises droplets of the ionic liquid catalyst having a diameter in the range from 1-1000 microns by choosing a combination of a static mixer element and a liquid linear velocity.
 29. The process according to claim 21, wherein the ionic liquid catalyzed hydrocarbon conversion is selected from the group consisting of: paraffin alkylation, paraffin isomerization, olefin oligomerization, cracking of olefins or paraffins, and aromatic alkylation.
 30. The process according to claim 21, further comprising: g) adding at least one of a co-catalyst and a catalyst promoter to the modular reactor, wherein the co-catalyst comprises an alkyl chloride and the catalyst promoter comprises HCl.
 31. The process according to claim 21, wherein step b) comprises maintaining the overall ionic liquid catalyst volume in the modular reactor in the range from 0.5 to 50 vol %.
 32. The system according to claim 1, wherein said static mixer modules comprise helical type- or plate type-static mixers that produce high turbulence and good radial mixing.
 33. The system according to claim 12, wherein said static mixer modules comprise helical type- or plate type-static mixers that produce high turbulence and good radial mixing.
 34. The system according to claim 18, wherein the first static mixer or the second static mixer is a helical type- or a plate type-static mixer that produces high turbulence and good radial mixing.
 35. The system according to claim 21, wherein the first static mixer module or the second static mixer module comprise helical type- or plate type-static mixers that produce high turbulence and good radial mixing. 